The objectives of this research are to determine the basic mechanisms that regulate the interactions between cytoskeletal keratin intermediate filaments and the cell surface associated adhesion junctions, desmosomes and hemidesmosomes, of gingival epithelia cells. The long term goal of the proposed studies is to gain insights into the molecular bases of the epithelial cell migration that represents a hallmark of periodontal disease. The specific aims include determining how the intermediate filament associated protein, IFAP300, connects desmosomes and hemidesmosomes to intermediate filaments. To this end, IFAP300 will be cloned and sequenced. Once the complete cDNA sequence is available, transient transfection will be used to determine the physiological functions of this important cross-bridging protein. Other aims are to determine in vitro the molecular interactions among keratins, IFAP300 and the major cytoplasmic plaque proteins of the desmosome (desmoplakin) and the hemidesmosome (BP230). In vivo studies will be targeted at determining the dynamic properties of keratin-intermediate filaments in living cells using microscopic imaging techniques.